It is generally known for single phase alternating current electric motors to be used from a relatively small size, from fractional horse power up to approximately ten horsepower and thereafter three phase motors are generally used up to very large applications.
In U.S. Pat. No. 4,446,416A to Cravens L. Wanlass, granted May 1, 1984, entitled “Polyphase Electric Machine Having Controlled Magnetic Flux Density” being either a motor or a generator, there is provided a stator core having main windings and additional control windings. The flux density is optimized in a polyphase machine by controlling the flux density in the stator core.
A main polyphase stator winding is wound on a magnetic core, the winding comprising a plurality of windings and each winding represents a single phase. Capacitors are connected with each of the windings in a series circuit.
The present invention is quite distinct and clearly stated in the description.
An additional motor winding technique is also known from the specification of German Patent Application No. 2508374 with a publication date of Sep. 9, 1976 and titled “Single Phase Induction Motor” to Wen, Hung-Ying. This patent application discloses only an induction of a single phase motor with two start windings so as to increase the start capacitor voltage. It also establishes a single phase induction motor with two sets of start windings, with better running power factor and improved starting torque.